Integrated fuel cell power system

ABSTRACT

The present invention is a fuel cell power system, with a fuel cell stack, a multi-function mounting plate, at least two fuel supply units, a distribution manifold, a gas pressure regulator, and a cover. The distribution manifold and gas pressure regulator may be integrated into the mounting plate. The mounting plate also serves as an end plate for the fuel cell stack. The system allows for continuous, uninterrupted use, since at least one fuel supply unit is removable, and the system can operate from another supply unit while the removable unit is being replaced.

RELATED PATENTS

The present application is a continuation of U.S. application Ser. No.10/126,165, filed on Apr. 18, 2002.

FIELD OF THE INVENTION

The present invention relates to fuel cell power systems.

BACKGROUND

Fuel cell power systems include a number of components, including thefuel cell stack, the fuel supply, a pressure regulator to control theflow of the fuel supply, and various tubes and fittings that serve asmanifolds for distribution of fuel through the system. Fuel cellstypically use hydrogen gas as a fuel but other fuels such as methylalcohol (methanol) or reformed hydrocarbons (reformate) may be used.

SUMMARY OF THE INVENTION

The present invention is an integrated fuel cell system, comprised of afuel cell stack or stacks, an integrated, multi-function mounting plate,fuel supply unit(s), a distribution manifold, a gas pressure regulator,and a cover. By integrating components, the present invention helpsimprove fuel cell operation, and lowers component count and assemblycosts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fuel cell system according to thepresent invention, without a cover.

FIG. 2 is a perspective view of a fuel cell system according to thepresent invention, with a cover.

FIG. 3 a is a perspective view of a fuel supply unit with a bayonetmount.

FIG. 3 b is a perspective view of another fuel supply unit with aspring-loaded mount.

FIG. 4 is a perspective view of a mounting plate according to thepresent invention, showing the internal gas distribution plumbing.

DETAILED DESCRIPTION

The present invention is an integrated fuel cell power system 10,comprised of a fuel cell stack 20, an integrated, multi-functionmounting plate 30, fuel supply unit(s) 40, 42, a distribution manifold50, a gas pressure regulator 60, and a cover 70.

As shown in FIG. 1, the fuel cell stack 20 is comprised of an array ofindividual fuel cells 22, and an end plate 24. The mounting plate 30functions as a fuel cell end plate. The integrated system of the presentinvention can work with virtually any polymer electrolyte membrane (PEM)fuel cell stack, including but not limited to stacks comprised ofintegrated fuel cells, or more conventional stacks comprised of fuelcells assembled from separate stand-alone components. The presentinvention can work with systems that use ambient or pressurized air asan oxidizer, either in natural convection mode or forced air mode.

As shown in FIGS. 1 & 4, the mounting plate 30 serves two functions.First, the plate serves as an end plate for the fuel cell stack.

Second, integrated within or attached to the mounting plate is a fueldistribution manifold 50, and a gas pressure regulator 60. The manifoldreceives fuel from the fuel supply units 40, 42. From the manifold, thefuel passes through the regulator 60 and into the stack 20. Thedistribution manifold contains valves 52, 54 for receiving fuel from thefuel supply units 40, 42. These valves engage complementary valve 44attached to the fuel supply unit(s). Both manifold valves 52, 54 and thefuel supply unit valve 44 are self-sealing, so that when the fuel supplyunits are removed from the manifold the valves close, ensuring that nogas will escape.

The manifold 50 distributes high pressure gas to the pressure regulator60, FIG. 1, through internal passages 56, 58 and regulator inlet port 62shown in FIG. 4.

The pressure regulator 60 reduces the pressure of the fuel gas so thatit is suitable for use by the fuel cell stack. Regulators of a suitabletype can be supplied commercially from different vendors, for example:Air-Logic, 5102 Douglass Avenue, Racine, Wis. The regulated fuel is thenconveyed out of the pressure regulator to the fuel cell stack 20 bypassing from the pressure regulator through the regulated gas pressureport 64 of the distribution manifold 50 and then through internalpassage 57 and into the fuel cell stack by way of the fuel cell inletport 66. The regulated gas can also be transmitted to the stack 20 fromthe regulator 60 through external piping hoses or tubes. The outputpressure of the regulator is adjusted or set by means of a set screw,knob, dial, or other output control means. The pressure regulator canbut need not be integrated with the mounting plate.

The mounting plate can be expanded to accommodate more than one set ofmanifolds and pressure regulators, so that more than one set of fuelcell stacks can be used with a single plate.

The fuel supply units can take many forms. As shown in FIGS. 1, 3 a, and3 b, they can be in the form of conventional pressurized gas storagebottles or methanol tanks. Additionally, metal hydride fuel cartridgescan be used, such as the “Hydrogen Storage System, Model Number ST-1-AL”supplied by ERGENICS, INC., 247 Margaret King Ave., Ringwood, N.J. Fuelcan also be supplied from an external source such as large pressurizedhydrogen gas bottles or other standard methods of supplying hydrogensuch as reformers. The units can connect to the distribution manifoldthrough a bayonet-type connection 46, as shown in FIG. 3, or throughother conventional methods known to those skilled in the mechanicalarts, including but not limited to a screw thread, or spring-loadedattachments 48. (FIG. 3 b).

The system of the present invention can be operated continuously,meaning that replacement fuel sources can be removed and reinstalledwhile the system is operating, resulting in uninterrupted use. In oneembodiment of the present invention, both fuel supply units areremovable fuel units, and a single spent fuel unit can be removed andreplaced while the system operates off the other one. In an alternativeembodiment, one fuel supply unit or cartridge is permanent and the otheris removable. The system can run off the permanent supply while theremovable supply is replaced with a fresh cartridge or other supplyunit. The permanent supply can then be refilled from fuel in theremovable unit. The permanent supply can take the form of a pressurizedgas bottle, a hydride cartridge, bladder, or other suitable container.Even those with little or no technical experience should have littletrouble replacing cartridges or other supply units within the presentinvention.

The fuel supply units are recharged or refilled using standard methodsused in the industry. The valve 44 opens automatically when connected toa charging or filling unit and when charged or refilled and removed fromthe charging or filling unit they then self seal and are ready forimmediate use.

As shown in FIG. 2, the cover 70 encloses the fuel cell system, butallows for easy access to the fuel supply units 40, 42. The fuel supplyunits 40, 42 can be removed without removing the cover 70. The cover hasslots 72 or louvers to facilitate proper air circulation.

One skilled in the art will appreciate that the present invention can bepracticed by other than the described embodiments, which are presentedfor purposes of illustration and not limitation. Various modificationsand changes can be made to the fuel supply units, valves, pressureregulators, mounting plate and the like without departing to the scopeof the present invention.

1. An integrated fuel cell power system, comprising: a. a stack of fuelcells; b. a mounting plate serving as an end plate for said fuel cells,said mounting plate comprising: i. a plate; and ii. a fuel distributionmanifold for receiving fuel and distributing fuel, said manifoldassociated with said plate; c. a gas pressure regulator connected tosaid fuel distribution manifold; and d. a fuel supply unit associatedwith said plate.